DR. A. GAMGrEE ON THE ACTION OF NITRITES ON BLOOD. 
603 
From this observation it would appear that although nitrites diminish to a remarkable 
extent the capability which venous blood possesses of absorbing oxygen, yet they do not 
abolish it entirely. The action was such, however, that highly venous blood did not 
absorb more oxygen than average samples of thoroughly arterialized blood would have 
done. 
IV. In this experiment, before acting upon the blood with nitrite of sodium, it was 
treated for half an hour with a rapid stream of carbonic acid. The object of this was 
partially to reduce the blood before acting upon it. The blood used was that of the 
Sheep, defibrinated. After passing the gas through it for half an hour, the blood, when 
examined in thin layers, presented a decidedly venous hue. It was then treated with 
nitrite-of-sodium solution. Two cub. centims. of the same solution as was used in the 
last experiment were added to every 25 cub. centims. of blood. Carbonic acid was then 
again passed through the blood. 
Twenty cub. centims. were then introduced into the laboratory-tube, and a previously 
measured quantity of atmospheric air was passed from the eudiometer into the laboratory 
tube. On shaking the laboratory tube a considerable evolution of gas took place, so 
that when replaced into the mercurial trough a considerable quantity of mercury was 
expelled, and the quantity of gas in it appeared very sensibly increased. 
After a contact of twenty hours the gas was decanted from the blood, measured, and 
analyzed. 
Volume of blood taken 
Atmospheric air brought in contact with the blood 
After contact with the blood for twenty hours 
After absorption of carbonic acid 
After addition of hydrogen 
After explosion 
In 100 parts of gas. 
Oxygen 15-9 
Carbonic acid . . . 21*07 
Nitrogen .... 63*03 
KHKK) 
Volume of atmospheric air taken 255*4 vols. =47*37 cub. centims. at 0° and 0 m *76 
Volume of O in air taken (calculated) 53*53 vols. 
Volume of O remaining . . . . 51*25 „ 
Amount of oxygen absorbed by blood= 2*28 vols. = 0*421 cub.centim. at 0°C. and 0 m *76. 
The above experiment confirms the results of those previously described, as the 
amount of oxygen absorbed by blood which had been for a considerable time treated with 
carbonic acid was not as great as that absorbed by the same amount of the most arteri- 
alized blood. It is interesting, moreover, as furnishing an example (although an exag- 
20 cub. centims. 
255*4 vols. 
322*2 „ 
254*3 „ 
388*96 „ 
235*20 „ 
